21521002141 has 4 divisors (see below), whose sum is σ = 21521582784. Its totient is φ = 21520421500.

The previous prime is 21521002133. The next prime is 21521002147. The reversal of 21521002141 is 14120012512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21521002141 - 2³ = 21521002133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21521002147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230635 + ... + 310216.

It is an arithmetic number, because the mean of its divisors is an integer number (5380395696).

Almost surely, 2^21521002141 is an apocalyptic number.

It is an amenable number.

21521002141 is a deficient number, since it is larger than the sum of its proper divisors (580643).

21521002141 is an equidigital number, since it uses as much as digits as its factorization.

21521002141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580642.

The product of its (nonzero) digits is 160, while the sum is 19.

Adding to 21521002141 its reverse (14120012512), we get a palindrome (35641014653).

The spelling of 21521002141 in words is "twenty-one billion, five hundred twenty-one million, two thousand, one hundred forty-one".